


The Game Keys

by EmpressShu1



Category: Fairy Tail, Undertale
Genre: Action, Comedy, F/F, F/M, Fluff, Frisk is Gender Neutral, Idk how celestial spirits really work, Romance, bc sans has rib-tickling jokes, bc soriel is totally canon, but it’s fiction so it’s fine, everyone likes a mama goat, fluffy ships, frisk is mute, i want papyrus’ spaghetti, lucy is kinda a hoe but it’s cool, mama goat absolutely hates asgore, sans is kinda sus bro, undyne is just like Erza tbh
Language: English
Status: Completed
Published: 2020-11-19
Updated: 2020-11-19
Packaged: 2021-03-10 02:35:10
Rating: General Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 3,025
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27626168
Author URL: https://archiveofourown.org/users/EmpressShu1/pseuds/EmpressShu1
Summary: As Lucy Heartfilia comes home from her book's award ceremony, she is paid a visit by the Celestial Spirit King himself. He gifts her with 10 brand new spirits called the 'Game Keys'. Lucy tries her best to befriend and control the rambunctious group of souls that are now contracted to her, but their new bonds are tested when a Dark guild that specializes in soul experimentation challenges Fairy Tail.Lucy will have to show true mercy and love towards the ragged collection of monsters that have no choice but to call her 'home'.
Relationships: Alphyne - Relationship, soriel - Relationship, tiny nalu, tiny tiny gruvia
Comments: 4
Kudos: 18





	1. New keys?

**Author's Note:**

> This is a crossover fan fiction of Undertale and fairy tail  
> If u no like it, then u no have to read it  
> The end  
> Amen  
> Enjoy

The whole town seemed to be sleeping, drunk on the deep blue of the night sky. The stars watched from above as Lucy walked home, high heeled shoes in hand, it had been a VERY long night.  
Sure, it was great that her book had been honored, but why did she think it was a good idea to invite the rest of Fairy Tail to the ceremony? Cana had drunk everything in the entire awards center, Juvia started stripping INSTEAD of Grey, and on top of all of that, Natsu had sneezed and accidentally set fire to the tablecloths. “I can’t believe them” she said aloud disparagingly to the sky as she swung her black pumps around her. “They all promised to be on their best behavior…. HAH! like that would ever happen”. 

Lucy was nearly ready to laugh about the whole thing as she unlocked the door to her apartment, after all, she loved Fairy Tail, no matter how rambunctious they can be at times. She opened the door, ready for a warm bath and a good night’s rest.  
The resigned smile slipped of her face as she beheld the usual sight of Nastu and Happy, asleep on her sofa.  
“WHAT ARE YOU TWO DOING HERE?!” she yelled as she awoke them with a non-too-gentle Lucy Kick. Happy opened his sleepy, giant eyes, “Why are you being so stingy Lucy? We’re here all the time!”  
Lucy’s jaw dropped, “That’s the PROBLEM cat! So, get yourself and the pyro, OUT OF HERE!!” Happy sighed and waddled over to the, still sleeping, Natsu. Lucy went to go put her shoes and purse away as Happy prodded Natsu with his little paws, trying to wake him up. 

Lucy heard the faint bits and pieces of Happy’s efforts to wake the sleeping Dragon Slayer, “Natsu…..up……we……go…..Lucy mad!.....-ome on!” As Lucy re-entered the room, she heard Natsu’s protests, “What? Why? I’m trynna sleep so….zzzzzz”  
Happy smacked him in the nose to wake him up again and Lucy began to drag him towards the door by his leg. Natsu sat up and yawned, “alright, alright, don’t gotta be so pushy about it……. what do you want me to tell the other guy?” He said while jutting his thumb toward her back window. 

Lucy felt her nerves steel, it was Grey wasn’t it? 

Lucy gritted her teeth and marched over to the window “Of course he’s here too”. 

And where Grey goes Juvia goes, and Erza is most likely here too, and probably the whole guild while they’re at it. Lucy opened the window and stuck her head out as she said, “Alright, everyone just needs to LEAVE right…. now?” 

Lucy felt herself trail off as she beheld, not Grey, not Erza, not even Juvia, but a huge mustached face bending down to see her.

“Well, if I am disturbing you, I can certainly come back another time” The Celestial Spirit King said as he straightened up, folding his gigantic arms over his armored chest.

Lucy tried to speak, but her mouth had gone dry. ‘Why is he here? I didn’t…. I didn’t break any keys…. did I?’ she thought as she haphazardly pulled out her beloved keys to check each one.

She breathed a sigh of relief as she saw each one just as she left them. Now calm, she looked up at the royal spirit again, “What are you doing here ‘stach-face?” she said before she could stop herself. The nickname, once again, didn’t appear to bother the King as he smiled and bended down again to speak to her. “Old Friend, I have come to ask for your assistance yet again.” 

Lucy’s thoughts immediately went to the spirits that she was as close to as any other member of her Fairy Tail family. Startled, she gripped her key ring and said, “Are they ok? Is the celestial world alright? Is it the eclipse again? Is Aquarius….” Lucy had to cut herself off before the tears she knew were coming, could actually surface. Happy and Natsu looked at each other and then walked up to the window besides Lucy’s trembling form. Lucy was surprised to feel a hand on her shoulder but immediately knew it was her friend. Lucy took a deep breath as the King smiled at her reassuringly, “Yes, your friends are safe, as am I, along with the rest of our world.” 

Happy put his little paws on his hips and stared straight up into the King’s enormous face, “Then what do you want with Lucy? She’s already done so much for you, give her a break, you sho— “  
“ HAPPY!” Lucy cut him off as she grabbed him and held him, “The King is my friend Happy, and I want to help him and the other spirits as much as I can.” 

The Celestial King’s smile grew even bigger, “I knew you would say that, old friend. However, I anticipate that this will not be a difficult request for you to accept.” Lucy opened her mouth, and then shut it again as he continued his speech, “You see, there are many other spirits in the spirit world, not just the stars.” Lucy nodded, she already knew this, having asked Grandpa Crux once about the Spirit world. 

The King continued, “Recently, a whole new batch of souls were reborn as spirits, I offered them contracts and keys, and they accepted.” The King put his fist next to the window and opened it to reveal 10 shining keys, in a multitude of colors and designs. “These are the Game Keys. My Good friend,” The King said, smiling, “You treat your spirits with love and respect, they are your friends, and you theirs. I can think of no better contractor for these new spirits than you.” 

Lucy felt her jaw fall again, ‘all of these keys’ she thought ‘they all are going to me mine to wield?’. 

She reached forward and touched next to where the keys lay on the King’s hand, she felt tears gather in her eyes, “You really trust me that much ‘stache-face?” She said as her other hand laid over her heart. 

The King looked down warmly at the keys in his own hand, “So, do you accept my request? You will look after the Game Keys? I only ask that you love them as your own, as you have done with your own spirits”. 

Lucy felt a pain in her cheeks and realized that she was grinning wide and proud, “OF COURSE!! Thanks ‘stach-face!” She exclaimed as she picked up all of the new keys in her hands, they felt warm, pulsing with the energy of her brand-new friends


	2. The Heart

**Notes for the Chapter:**

> The art be mine  
> So credit  
> Pls

  
https://pin.it/4BMMEiT

The Next Day 

“Ok! Its time, I am going to make contracts with 10 new spirits today!” Lucy said as she surveyed the 10 shining keys that she had spread out over her coffee table. “But I have one question?....” She says as she looks up from the keys and around the room,

“…WHAT ARE ALL YOU GUYS DOING HERE???!!”

‘Guys’ was, of course, referring to Natsu, Happy, Erza, Grey, Wendy, and Carla.

“I expected Natsu and Happy because they were here when I got them, but why is the whole TEAM here?!” Erza looked serenely at Lucy, “Well, Happy told me that you had new spirits, Congratulations were in order.” Lucy looked over to the rest of them to hear their reasons. Grey frowned, “These new spirits are going to be a part of our team too Luc, you can’t expect us not to be curious”

Wendy nodded as she hugged Carla tight, gazing over all of the glistening Keys in front of her, “WOW Lucy! There are so many! You must be so excited! This one is pretty!” she said, pointing to a small gold key with a large heart decorating the handle.

Lucy sighed, leaning her head on the table, “I really shouldn’t have expected anything different, but honesty, I guess you’re right Grey, these are you guys’ new friends too!” She said, picking up the key Wendy had pointed to. “I guess I should get to it then! Would you like me to do this one first Wendy?”

Wendy bounced up and down on the chair but was cut off by Natsu standing up and shouting, “FORGET ABOUT THE PRETTY ONE!! I SAY WE PICK THIS ONE!” as he picked up a bone-colored key. “I noticed it before! It looks sort of like a dragon!” Natsu shoved it into Lucy’s hands and she examined it more closely.

Lucy felt everyone gather over her shoulder to see the key,

Wendy touched it gently with a finger as she said, stunned, “y... you’re right Natsu…. It really does look almost like a dragon! Do you think it’s a dragon spirit?”

Natsu practically vibrated with energy and excitement, “AW YEAH!!! Maybe I can practice my Dragon-Slaying magic on it!!”. Lucy’s eyes widened and she snatched the key back and held it against her chest, “NO WAY!” Natsu stopped bouncing and looked at her, “WHAAAAT? Whhhhhy?”

“I’ve told you Natsu, my spirits are my friends!” Happy looked over and patted Natsu on the leg, “Yeah and I remember something about the King spirit saying something about trusting Lucy BECAUSE she treats them so well.” Natsu looked down at Happy and then back at Lucy, clutching the key with her life, and sighed, slumping back down onto the sofa with Erza, Wendy, and Grey.

Carla sniffed her nose up at him from her vantage point on Wendy’s lap, “Besides she asked Wendy, not you! You should set a better example for her and act your age.”

Wendy, flushed as attention was returned back to her, “No! It’s ok, we don’t have to do mine, I’m curious about the dragon one too….”

Lucy looked at her and then back down at the gold key in front of her, making a decision,

Lucy put the ‘dragon key’ back down onto the table and picked up the simple gold one. It wasn’t too ornate and looked fragile so she held it carefully, turning it around so that she could see the name engraved onto the side. “Frisk the Heart” she read aloud. Happy frowned, “Didn’t that big guy say that these were called the ‘Game Keys? What does a frisky heart have to do with a game?”

Erza folded her arms and leaned back into the couch, “Well,” she said, glancing over at the key, “I assume it means the ‘heart’ cards in a deck of cards.” Happy ‘oooooohed’ and everyone leaned forward as Lucy raised the key towards the ceiling, she took a breath before speaking in a voice full of anticipation and resolve.

“I call upon you from the Spirit world, I ask you to pass through the gate and I beckon you to my side,” Lucy swiped the golden key downwards as it began to glow faintly, “Come, Frisk the Heart!” All at once, a portal opens up above where Lucy was standing.

The portal swirls with an epiphany of colors and shades, and everyone looked up expectantly. And what eventually come through the circular rainbow, is a falling rain of scattering golden flowers. The flowers fall into a haphazard pile in front of Lucy, drifting slowly towards the ground. And then, something else falls through. The something isn’t very large; it falls onto the flowers with a gently muffled ‘thump’. Lucy walks over to see it better, but freezes again as the bundle of soft brown, blue, and purple, begins to move.

The spirit struggles to their small feet and wobbles a bit before looking around at them. ‘Frisk the Heart’ sees so many people with their attention focused solely on them and blushes bright pink. Lucy smiles, taking in the tousled brown hair, the oversized sweater and the nervous hands,

‘This spirit is SO CUTE!’ she thinks as said spirit blushed deeper, trying to bury themselves into their striped clothes. Lucy steps forward, grinning wider than ever, “Hello! I’m your new contractor Lucy! You must be Frisk?” she says as she extends her hand for a handshake. Frisk pulls their head out of their sweater and gives her a tiny smile, nodding as they take two of her long fingers in their tiny, chubby hand. Lucy gives their little hand a gentle shake and then let’s go.

Happy nearly surprises the child out of their skin as he flies over to see better.

Happy looks closely at their rosy face and giggling, “Lucy, I think you did something wrong, it a kid!”

Lucy is about to throw Happy away from the frightened child until they see a large smile break out a crossed Frisk’s face. Happy doesn’t have time to think before Frisk has grabbed him into a tiny hug, small arms wound tightly around the confused, flying, feline. “LUCY! HELP! IT GOT ME!!” Happy yells from the gap in between Frisk’s face and arm.

Everyone laughs as Frisk plops back down onto the flowers with Happy clutched in their small hands, something about his spirit just brings warmth into their hearts. A small smile was adorning everyone’s face, even Happy, as he protests, has a small grin a crossed his blue cheeks. “Hey, looks like you made a friend Happy!” Natsu says, smiling his giant smile down towards the spirit. ‘They may not be a dragon,’ he thinks ‘but it’s still friendly, and that something!’. Lucy realizes that Frisk now has their gaze fixed patiently on her face, and snaps back into reality.

“Right! We have business to do! Now, I can’t wait to get to know you better, Frisk but FIRST, we have to get our contract in order.” Lucy reaches into her skirt pocket and pulls out her small notepad and pencil, kneeling on the ground in front of the child. “Alright,” she says, gazing back at the well-behaved, child-spirit in front of her, “What’s your specialty? Are you a companion spirit? A combat spirit?”. The child sticks out their lip as they think, then, they simply nod.

Grey begins realizing that this kid hasn’t uttered a word this whole time, “Hey Luc, do you know if they even speak?” he says to the Celestial mage. Lucy’s eyebrows shoot up and she puts a hand over her mouth, “Oh no! I didn’t even think to ask! I’m sorry Frisk!” Frisk smiles and waves their hand in a, clearly dismissive, wave. “Ok,” Lucy continues, “do you speak?” Frisk shakes their head shyly but then straightens, pointing at the pencil Lucy had in her right hand. Lucy looks at the said pencil and understands,

“Oh! You can write?”. Frisk nearly blinds her with a gigantic, baby-teeth, white smile as they nod excitedly; greatly resembling a bobblehead on display at a gift shop. Lucy fumbles around, looking for more paper and pencils, until Erza remembers an item in her requip storage dimension. She quickly requips it into her hand, and holds it out, close enough for Lucy to take it, “I have this light pen, if that is suitable.” Lucy grins and snatched the pen, “You’re a genius Erza, this way, I won’t have to carry around paper all the time!” Lucy hands the pen towards a bewildered looking Frisk, “Try this, it’s a light pen, you can use it to write in the air!” Frisk releases Happy, and takes the pen with two, almost reverent, hands.

‘I hope they like it…’ Lucy wonders as she begins to sweat nervously.

Frisk uncaps the pen and draws a hesitant smiley face in the air, then clicking it to erase it, a relieved breath leaves Lucy as Frisk stand up excitedly, writing out, “Thank you so much! It’s so nice to meet you!” then, Frisk all but jumps into her arms, hugging her neck. Lucy laughs and after a, rather nice, snuggly hug, and Frisk asking everybody’s name accompanied with a hug for each surprised wizard, they both resume their positions on the floor.

“So, now that you can actually answer me,” Lucy begins again, notepad in hand, “What do you do?”

Frisk thinks and then writes in front of them, “I don’t really fight, so a companion spirit I think?”

Natsu and Grey sigh pointedly and Frisk looks at them startled, “But I’m not useless! I can’t die or be sent back to the spirit world unless I chose to go back! And I can pull other spirits out of their keys, without you summoning them, using my own energy!”

Shocked, Lucy looks at them, “That’s crazy! So, you could summon one of these other spirits on your own? Without me?” she says as she gestures at the 9 other keys, lying together on her coffee table.

Lucy gulps, stepping aside, “If you don’t mind, could…could you show me?”

Frisk immediately dives for a large, purple key, embedded with gems in a peculiar looking rune.

They smile up at all of them, writing as they clutch the key in one pudgy hand, “I could introduce you to my Mama if you want? She’s really nice!” Lucy looks at the smiling spirit, shifting her weight to one hip, “Your mom? Are all of you like a family?”

Frisk looks lovingly down at the other keys, “Well, not really… mostly, we’re all kind of just like friends who are as close as family.”

Erza smiles as she looks around at her precious friends and knows exactly how Frisk feels, “We can understand that sentiment perfectly. And I, for one, cannot wait to meet your mother.” Frisk giggles specially for the red head and runs over to the more open part of the room. When Lucy moves to stand next to them, they hold step back further, “Mom is going to need some room in order to come over” they write with a sheepish smile. “Oh, alright” Lucy says, before an image of the enormous Pisces flashes in her mind,

“…WAIT! JUST HOW BIG IS SHE?” Frisk smirks in an obvious, ‘you’ll see’ expression, and kisses the key; where it immediately begins to glow softly in their hands. 


End file.
